Cannot install Rmarkdown

I can not install R Markdown. The message is "Creating R Markdown documents requires updated verions of the following packages: Rcpp, base64enc, htmltools, jsonlite, knitr.... "

Do you want to install these packages now?

When I click yes --> failed job.

Could you please help me to solve this problem?

Please share the error you're getting verbatim.

You should try running the command,

install.package("rmarkdown")

prior to trying to knit a document.

My error is following, I cannot install Rmarkdown:

** Installing R Package Dependencies for R Markdown: 'Rcpp', 'base64enc', 'htmltools', 'jsonlite', 'knitr', 'mime', 'rmarkdown', 'stringi', 'stringr', 'tinytex', 'xfun', 'yaml'

[1/12] Installing Rcpp...

trying URL 'https://cran.rstudio.com/bin/windows/contrib/4.0/Rcpp_1.0.5.zip'
Content type 'application/zip' length 3265833 bytes (3.1 MB)

downloaded 3.1 MB

package 'Rcpp' successfully unpacked and MD5 sums checked
Error in unpackPkgZip(foundpkgs[okp, 2L], foundpkgs[okp, 1L], lib, libs_only, :
ERROR: failed to lock directory '\ad.monash.edu\home\User079\hpha0021\Documents\R\R-4.0.2\library' for modifying
Try removing '\ad.monash.edu\home\User079\hpha0021\Documents\R\R-4.0.2\library/00LOCK'
Calls: sourceWithProgress ... eval -> -> .install.winbinary -> unpackPkgZip
Execution halted

Navigate to ad.monash.edu\home\User079\hpha0021\Documents\R\R-4.0.2\library/ and delete the 00LOCK folder and try again.

I solved that problem. But I faced new problem
pandoc.exe: assessment1template.utf8.md: openBinaryFile: does not exist (No such file or directory)
Error: pandoc document conversion failed with error 1
Execution halted

Could you please help me?

This is a different question and we like to keep things tidy around here so, Could you please ask it on a new topic?